Many implantable medical devices, such as neurostimulators, pacemakers and defibrillators, transmit electrical signals to provide therapy to a patient. Electrical signals generated by the devices may be delivered to the tissue of a patient via one or more electrodes disposed at a distal end portion of a medical lead, which may be connected to the signal generator with a lead extension.
Typically nervous tissue is targeted by the electrical signals. In some cases the target may be a specific nerve fiber. In other cases the target may be specific nerve fascicles. In contrast, broad targeting of a nerve can have undesired consequences. For example, if a nerve is targeted for treatment of pain, selective targeting of afferent fibers, as opposed to efferent fibers, would be desired to avoid undesired motor side effects. Accordingly, targeting selected fascicles of a nerve would be preferred over broad targeting of the nerve.
However, such selective targeting of nerve fascicles can be difficult, as the fascicles do not often run in a nerve through a straight line. A lead having electrode configurations capable of facilitating selective capture of desired fascicles of a nerve would be desirable.